Field of the Invention
The invention relates to a tong system provided for use in a drilling rig for deep drilling, for example for sinking holes over hydrocarbon deposits for oil and gas exploration or for geothermal development, which in the professional terminology frequently is also termed a “floorhand” or an “iron roughneck,” and also can be termed an automatic rod tong.
Description of the Related Art
U.S. 2007/068669 A describes such a tong system. The invention also relates to a clamping block of such a tong system.
A generic tong system is provided when mounting and dismounting the drill rod for connecting two drill rod elements or for disconnecting two drill rod elements, in particular for connecting one drill rod element to the drill string or to release a drill rod element from a drill string. For this purpose the tong system is moved by means of a movable arm or the like in the region above the borehole or a region above the so-called mouse hole. There a drill rod element is connected to a stationary drill rod element or a drill rod element is separated from a stationary drill rod element. The stationary drill rod element is for example stationary as a component of the drill string or because of placement in the mouse hole. For better readability—but without dispensing with further general validity—the following description is continued with reference to a stationary drill rod element as a component of the drill string and use of the tong system over the borehole.
By means of a lower tong included in the tong system, in a manner known per se first the tong system is fixed to the stationary drill rod element. By means of an upper tong that is movable in relation to the lower tong, then—in a manner likewise known per se—either connection of a further drill rod element to the stationary drill rod element or disconnection of the drill rod element from the stationary drill rod element occurs.
In the process, precise positioning of the tong system above the stationary drill rod element is important.